@NUGG4TZ: No, the suit isn't prophet, the suit just knows his DNA, memories and his mind. The suit became a "part" of prophet but it is not prophet himself, it's like a bodypart of him able to think and such. But it can't live without a host, and that's Alcatraz. Why does anybody think that Alcatraz has to be dead if the suit is/was a part of Prophet? Alcatraz uses the suit and Prophet "is" in one way the suit, and the suit performs symbiosis, so Alcatraz and Prophet are merging. They both think as one and do as one. That's what I think.
I agree with this.
At least, this was my train of thought after finishing the game last night

As for "not having a boss battle", did it really need one?
I thought the giant mech battles were awesome enough, I kinda liked the way it ended.
No, I guess you are right. An action sci-fi shooter does not need a boss fight ending. Just some a dude crawling up to an edge and falling over, a silly plot expansion, and an american flag waiving in the wind.
On top of that, Tetris did not have a boss fight either and Tetris has an even better ending than Crysis 2, I think...does anyone know if Tetris ever ends?